btrfs: introduce mount option rescue=all

Now that we have the building blocks for some better recovery options
with corrupted file systems, add a rescue=all option to enable all of
the relevant rescue options.  This will allow distros to simply default
to rescue=all for the "oh dear lord the world's on fire" recovery
without needing to know all the different options that we have and may
add in the future.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/super.c

@@ -362,6 +362,7 @@ enum {
 	Opt_nologreplay,
 	Opt_ignorebadroots,
 	Opt_ignoredatacsums,
+	Opt_rescue_all,
 
 	/* Deprecated options */
 	Opt_recovery,
@@ -461,6 +462,7 @@ static const match_table_t rescue_tokens = {
 	{Opt_ignorebadroots, "ibadroots"},
 	{Opt_ignoredatacsums, "ignoredatacsums"},
 	{Opt_ignoredatacsums, "idatacsums"},
+	{Opt_rescue_all, "all"},
 	{Opt_err, NULL},
 };
 
@@ -512,6 +514,15 @@ static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
 			btrfs_set_and_info(info, IGNOREDATACSUMS,
 					   "ignoring data csums");
 			break;
+		case Opt_rescue_all:
+			btrfs_info(info, "enabling all of the rescue options");
+			btrfs_set_and_info(info, IGNOREDATACSUMS,
+					   "ignoring data csums");
+			btrfs_set_and_info(info, IGNOREBADROOTS,
+					   "ignoring bad roots");
+			btrfs_set_and_info(info, NOLOGREPLAY,
+					   "disabling log replay at mount time");
+			break;
 		case Opt_err:
 			btrfs_info(info, "unrecognized rescue option '%s'", p);
 			ret = -EINVAL;

fs/btrfs/sysfs.c

@@ -334,6 +334,7 @@ static const char *rescue_opts[] = {
 	"nologreplay",
 	"ignorebadroots",
 	"ignoredatacsums",
+	"all",
 };
 
 static ssize_t supported_rescue_options_show(struct kobject *kobj,